1. Field of the Invention
This invention relates to medical devices for use with humans and animals, and specifically relates to enterostomy devices for insertion in the stomach or intestine to provide delivery of nutrients and other substances directly to the gastrointestinal tract of patients who cannot be fed by other conventional means.
2. Statement of the Art
It frequently becomes necessary in the medical treatment of humans and animals to provide nutrients or other substances to the patient's stomach by means other than the mouth due to the existence of some condition in, or relative to, the mouth or esophagus which renders impossible the normal intake of fluids or nutrients through the mouth. Such conditions may include, for example, a localized disease condition of the mouth or esophagus or the inability of the patient to chew or swallow. Delivery of fluids or nutrients to the patient's stomach may be provided in one of three generally-recognized methods—namely nasoenteric tube placement, gastrostomy or jejunostomy. Feeding via nasoenteric tube involves the positioning of one or more tubes through the patient's nostrils, through the nasal passages to the throat and down the esophagus to the stomach. Gastrostomy involves the formation of a stoma, or opening, through the patient's abdominal wall and stomach, followed by placement of a tube through the stoma for delivery of fluids and nutrients directly to the stomach. Jejunostomy involves the formation of a stoma through the lower abdominal wall and the intestine, followed by the insertion of a tube through the stoma and into the intestinal tract.
Each type of feeding identified above has its appropriate applications and contraindications. For example, nasoenteric tube insertion is suitable for temporary or short term feeding requirements, but is unsuitable where the patient cannot tolerate the placement of such tubes or where feeding must be continued for longer than a week or two. Gastrostomy is appropriate for longer periods of required feeding (e.g., more than four weeks) and has the particular advantage of using the stomach's storage capacity, osmotic regulation and prolongation of intestinal transit to maximize the intake of nutrients. Gastrostomy, however, may not be suitable where the stomach is in a diseased condition, where there is abnormal gastric emptying, significant esophogeal reflux or lack of inherent gag reflex in the patient. Jejunostomy is appropriate where gastrostomy is contraindicated by one of the aforementioned conditions, but is less desirable than gastrostomy because of the shortened period of time that the nutrients may be absorbed by the intestinal tract.
A number of gastrostomy and jejunostomy devices have been developed over the years to supply a fluid-communications port to the stomach or intestine. Examples of gastrostomy and jejunostomy devices are disclosed in U.S. Pat. No. 5,549,657 to Stem, et al.; U.S. Pat. No. 5,411,491 to Goldhardt, et al.; U.S. Pat. No. 5,391,159 to Hirsch, et al.; U.S. Pat. No. 5,356,391 to Stewart; U.S. Pat. No. 5,342,321 to Potter; U.S. Pat. No. 5,336,203 to Goldhardt, et al.; U.S. Pat. No. 5,080,650 to Hirsch, et al.; U.S. Pat. No. 4,861,334 to Nawaz; U.S. Pat. No. 4,850,953 to Haber, et al., and U.S. Pat. No. 3,915,171 to Shermata.
Previously disclosed enterostomy devices are generally configured in a similar manner to deliver nutrients to the stomach or intestine. Specifically, they comprise a tube which is positionable through a stoma or opening formed through the patient's abdominal wall and stomach or intestine, a retainer device positioned at one end of the tube which is located within the stomach or intestine, and a valve device positioned at the end of the tube opposite the retainer device. The valve device provides at least one opening through which fluid can be introduced to flow through the tube. The valve device may also serve to maintain the tube in position within the stoma and often provides a means by which the tube may later be removed from the stoma.
The retainer devices of previously disclosed gastrostomy devices generally function well for their intended purpose (i.e., anchoring the gastrostomy device to the stomach or intestinal lining and delivery of substances to the gastrointestinal tract), but they are almost uniformly rendered disadvantageous in being large or potentially obstructive in configuration. That is, the design or configuration of the retainer device of most known gastrostomy devices is such that it extends a significant distance into the lumen of the stomach or intestine, thereby causing an obstruction of the stomach or intestine, or the retention device extends so far into the stomach or intestine that it contacts tissue on the opposing side of the stomach or intestine causing irritation or infection. Further, the configuration of some known devices provides an insufficient surface area for contact with the stomach or intestine lining, which can result in dislodgement and accidental removal or expulsion of the gastrostomy device from the patient's body. Additionally, most gastrostomy devices provide an aperture, in axial alignment with the feed tube of the device, through which nutrients are feed and, oftentimes, through which fluids are vented from the stomach or intestine. To prevent entry of infectious agents or accidental release of fluids from the stomach or intestine through the gastrostomy device, many known devices provide a tethered plug which can be inserted into the aperture. In such devices, trauma to the stoma occurs when a syringe or tube set is inserted in the axially-aligned aperture and trauma also occurs to the stoma when the plug in inserted and removed from the aperture.
Thus, it would be advantageous to provide an enterostomy device which is structured to provide a retaining member having an increased area of contact with the stomach or intestinal lining, thereby preventing premature or unintended release of the device from the patient, and one which is unobstructive in configuration to prevent blockage in the stomach or intestine. It would further be advantageous to provide a enterostomy device which is structured with a low-profile valved hub which eliminates trauma imposed on the stoma as is typically experienced with known gastrostomy devices.